[PATCH] doc: Locking update

Make the Locking document truer.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Nikita Danilov 2005-05-01 08:58:37 -07:00 committed by Linus Torvalds
parent bd53b714d3
commit 2054606ad6

View File

@ -219,8 +219,12 @@ This may also be done to avoid internal deadlocks, but rarely.
If the filesytem is called for sync then it must wait on any
in-progress I/O and then start new I/O.
The filesystem should unlock the page synchronously, before returning
to the caller.
The filesystem should unlock the page synchronously, before returning to the
caller, unless ->writepage() returns special WRITEPAGE_ACTIVATE
value. WRITEPAGE_ACTIVATE means that page cannot really be written out
currently, and VM should stop calling ->writepage() on this page for some
time. VM does this by moving page to the head of the active list, hence the
name.
Unless the filesystem is going to redirty_page_for_writepage(), unlock the page
and return zero, writepage *must* run set_page_writeback() against the page,